With the development of the Internet, a distributed system cannot better satisfy network scalability and a requirement for management, and therefore, a centralized system in which controlling and forwarding are separate, such as an OpenFlow system, emerges as required. A control device, such as a main control device (Master), and a network device managed by the control device, such as an access point (AP), jointly complete a packet forwarding process that is completely controlled by a switch/router originally, thereby implementing separation of data forwarding and routing control. As network devices increase, each network device needs to compute a packet forwarding path from the network device to a corresponding control device, and uses the Link Layer Discovery Protocol (LLDP) to send to the control device other information such as information related to the network device.
Each network device needs to compute a packet forwarding path from the network device to a corresponding control device, thereby causing an increase in a processing burden of the network device.